As spotted on Reddit, Rich Nelson is an extreme fan of paper-cut light boxes, so much so that he decided to make his brother — who lives in Philadelphia — a light box featuring that city’s skyline. Three layers are used to show the skyline, along with foreground imagery to give it perspective, all of which are lit up using daisy-chained WS2812 LED strips.
While that effect by itself is quite good, the really amazing feature of this build is that not only do these lights respond to the time via an Arduino Nano and an RTC module, but an image of the sun and moon passes over the skyline in the background. These celestial bodies obey actual time patterns, and the moon is even programmed to change phase according to the date.
Naturally, this took some creative hacking, and behind the layers of skyline, the light box contains a small servo to make the sun/moon — a small TFT display modified with a more powerful backlighting system — rise and fall. This clever display can even be set up to reveal the time and date numerically, enhancing the device’s usefulness beyond an amazing decoration.